A building window typically comprises a rectangular frame, often constructed from extruded lengths of metal or polymer or another material. The frame is arranged in an opening in a building wall having a given depth or wall thickness, and the frame carries a glass unit. In some windows, the glass is stationary and seals the opening. Advantageously, however, the glass unit can comprise a fixed pane and an overlapping movable sash pane, or two slidably overlapping sashes, one or more hinged casements, pocket panels or another movable structure by which the window is opened or shut selectively, namely by adjusting the position of its movable parts relative to the frame.
Windows have several useful aspects. These include, at least, admitting or blocking light and viewing, admitting or blocking air circulation, thermal insulation (conductive, convective and/or radiant) when closed, capacity to block rain or other precipitation or dampness, security against unauthorized entry or exit, etc. A window may be more or less effective for these particular functions due to the specific structure chosen. There are tradeoffs.
Windows also have important aesthetic effects. The size and character of an exterior window can vary the perceptions of those in a room in a building and those who view the window from the exterior. From the interior, for example, different sizes and structural arrangements can carry different impressions with respect to privacy and security versus public exposure, warmth in a cold climate or comfortable coolness in a hot climate. From the exterior, windows vary from welcoming expansive openings to forbidding security arrangements.
Among possible window structures, the jalousie type window comprises a plurality of slats or louvers that are mounted on parallel spaced pivot axes. Typically the pivot axes of the slats are horizontal but they can be vertical instead. The slats advantageously can be ganged by a linkage mechanism causing the slats to pivot open or closed in unison. Jalousies can have security benefits because the spacing between the slats is typically too small to admit an intruder in any pivot position of the slats. The slats can be pivoted into a position at least partly perpendicular to the plane of the building wall. When fully perpendicular, planar slats occupy the minimum cross sectional area obstructing air flow or view. Wholly planar parallel slat structures might be sized and spaced so as to pivot into a common plane when closed. Often the slats are configured for upper slats to overlap at their edges with lower slats when closed. In order to seal closed against the passage of air or light, the edges of the slats can have seals and/or can be shaped with stepped edges that are complementary to the shape of an adjacent slat. Slats may comprise sheet material that is flat, or curved across a lateral cross section. A curve tends to contribute stiffness. Slats may vary in thickness across a lateral cross section in a diamond or lozenge or other shape. These variations from a thin flat planar slat shape increase the apparent slat thickness when the slats are fully open.
Among other possible variations, the slats of a jalousie window can be relatively wider or narrower in a lateral direction perpendicular to the slat pivot axis, and might be centered and balanced on the pivot axis or off-center so as to cantilever when open. A smaller number of wider slats can encompass the same size window opening as a greater number of narrower slats, regardless of the relative placement of the pivot axis. But when the slats are opened, different arrangements produce different effects, for example as to sun shading, slat position and span of displacement of the slat edges in a direction perpendicular to the plane of the window, etc.
The jalousie slats can comprise clear glass, colored or translucent glass, or an opaque material such as sheet metal, wood or plastic, or painted or covered glass. Clear glass is desirable for viewing when opened or closed. Opacity is desirable for privacy when closed. A sheet metal material provides security.
Glass or otherwise transparent slats may promote interior illumination by allowing direct sunlight to enter the building through the glass. The direct light, however, may undesirably impact the interior temperature. The solar radiation may also damage the contents of the building or the jalousie slats themselves. Furniture and other upholstery may prematurely fade and wear. Glass jalousies may also present a security risk. They may allow malicious individuals on the exterior of the building to view interior contents, even when the slats are in a closed position. Additionally, glass slats may be easily broken by accident, malicious behavior, or environmental hazards.
In an effort to mitigate the concerns associated with glass jalousie slats, opaque alternatives may be used. Metal, wood, or plastic slats may shield a building's interior from harmful solar rays. They may also be more resilient and provide greater security from break-ins or environmental hazards. Opaque slats, however, may hinder the natural light entering a building. As a result, interior lighting solutions may be necessary. Additionally, while the opaque slats may protect the building's contents from damage, they are themselves susceptible to solar and environmental wear.
It would be desirable to provide a jalousie window assembly which promotes natural interior illumination, while avoiding the harmful side effects of solar rays. Doing so may be helpful in maintaining a comfortable and stable interior temperature in the building, and may impact energy costs by reducing the need for artificial lighting. Additionally, it would be desirable to provide an assembly which promotes this interior illumination without compromising the safety and security of a building's contents.
It would therefore be desirable to provide an apparatus which combines the illumination capabilities of transparent jalousies with the protective capabilities of opaque jalousies.